AJP - Endocrinology and Metabolism, Vol 263, Issue 3 E430-E434, Copyright © 1992 by American Physiological Society
Effects of thyroid hormones on urinary and renal kallikreins
S. Avigdor, F. Alhenc-Gelas and J. Bouhnik
Institut National de la Sante et de la Recherche Medicale U36 and U367, Paris, France.
The effects of thyroid hormones on the urinary excretion of kallikrein and
on renal kallikrein were studied in rats. Total and active urinary
kallikrein was decreased after thyroidectomy, but renal kallikrein content
remained unchanged. Diuresis increased, and kidney weight and plasma
aldosterone concentration decreased. Treatment with
3,5,3'-triiodo-L-thyronine restored the urinary kallikrein in
thyroidectomized rats to normal and increased it in intact rats. It also
produced increases in kidney weight and plasma aldosterone and a decrease
in diuresis. The effect of thyroid hormones on the urinary kallikrein
response to mineralocorticoids was also tested. Deoxycorticosterone acetate
increased urinary kallikrein more in normal than in thyroidectomized rats.
These results suggest that thyroidectomy decreases renal kallikrein
synthesis and lowers the turnover rate of the enzyme, changes not
detectable by a single measurement of the renal kallikrein content but
reflected by an alteration in the urinary excretion of the enzyme. Thyroid
hormones participate in the control of urinary kallikrein. This effect,
however, is probably indirect and may be mediated by mineralocorticoids
since thyroid function affects both the plasma level of aldosterone, which
is known to influence renal kallikrein, and the kallikrein response to
exogenous mineralocorticoids.
